It was a bit embarrassing.

Two highly sophisticated bus salesmen were driving a demo to show a customer . . . and the coach's floor was a muddy mess.

We had a mop but no bucket or water, and were only blocks from the operator's location. At the last possible moment, Robert (he also is a clever bus salesman) spotted a parking lot with a puddle.

We dipped the mop in the puddle and flailed up and down the aisle until voila -- a clean bus.

It's a given that a bus should be clean at the beginning of any trip. But sometimes the definition of clean gets blurred. Sweeping and mopping is certainly the minimum and may well be all that can be done during busy times.

But, because cleaners work year 'round, there may be things they can do during slow periods that will make your buses more attractive to customers who spend hours in them.

The outside of your windows are cleaned every time the coach is washed, but the inside is more important. Not only do passengers get to see the dirt, they also get to touch it.

Magazine nets on seat backs collect interesting stuff. Presumably they're emptied after every trip but they tend to hide things. The window-side ones are sneaky, perhaps because they're harder to reach.

Many buses use the cabin sidewall for HVAC ducting. It's remarkable what passengers stuff down there. You might want to remove the inside panel every year and clean. Consider rewarding the cleaner who finds the most unusual object. This will be both entertaining and educational. It's likely there will be a measurable improvement in your HVAC.

You also might consider, every couple of years, cleaning the floor duct that moves the HVAC air into the sidewalls, as well as the return air duct. Both collect dirt and impede performance.

Coaches with baseboard heating offer trash the opportunity to hide both under and in the coils. Even if you can't see it, the organic stuff will not improve with age.

Short-armed cleaners have difficulty with deep package racks. You really do want to thoroughly clean them, regularly, or you risk infestation with roaches or mice. Neither makes a good mascot and mice will eat the foam in seat cushions.

Many operators steam clean seats annually. This improves appearance and removes organic material that draws critters. Check the area between the seat cushion and back for hidden material.

While you're doing the seats, consider cleaning (or replacing) ceiling fabric. It picks up more dirt than you think, and holds onto smells.

Sprayed ether will often help remove chewing gum from fabric (the cold makes gum brittle so you can flake it out). If you try this, take special care, because mixing ether and an open flame results in a bright orange explosion that is decorative but destructive.

You might want to regularly check, and clean, under-floor baggage areas. Any food left there will eventually make the whole coach smell, and spilled liquids such as oil and bathroom chemicals will ruin expensive luggage.

Pay attention to the fuel filler. In some cases it's close to the HVAC (which will merrily spread the smell). In any event, spilled or leaked fuel will make the bus stink. Diesel fumes are nasty and very difficult to eliminate, so check often and solve problems quickly.

One important component on a modern coach is the lavatory exhaust fan. It's not always easy to be sure it's working but it's a key to keeping bathroom smells out of the cabin. Check it regularly. It's critical to dump the lavatory as soon as the coach returns home. Without being tacky, baked in the sun long enough, the contents can become ammonia, and ammonia is a big improvement over the interim product.

For the same reason, on longer moves, it's important that drivers service the lavatory more often than they think necessary. While they're doing that, it's not a bad idea to sweep and mop the coach. Your best drivers are already doing it, but you might mention to the others that sweeping will improve tips.

Keeping the floor clean isn't just an aesthetic improvement, it also keeps customers from slipping and falling on trash and prevents containers from becoming missiles in a sudden stop.

At this point you're probably wondering about a strange noise you hear in the background. Its the cumulative laughter of everyone who knows me, giggling uncontrollably at the thought of me writing an article on cleaning. Please don't tell my wife.

Dave Millhouser is an account representative for ABC Companies. Contact him at: dmillhouser@abc-companies.com.