Speaking as a former corporate traveller, I can well understand these guys fears of discovery.
If these guys have to travel with a coworker, ditching that coworker can be a bitch. Also, if you're in the same hotel, you can be assured they're watching you just as much as you are watching them. (Okay, maybe the corporate evironment I was in was dysfunctional and cutthroat, but I saw more than one person lose their job because of what some management ass thought was "inappropriate" behavior on the person's part that happened while they were travelling for the company)
It is not the same as travelling on vacation. Like it or not, the business traveller is representing his company 24/7. Some of these companies, all it takes is an anonymous call to the wrong guy within the company and goodbye job. Doesn't matter if the info is true. Rumor is hard to fight.
I think the idea of non-business attire is a great one. Look at the threads here that are devoted to scoring guys in hotel saunas and workout areas. (plus the eyecandy there is usually very nice)
Bluejeans, loafers and a nice golf shirt will get you noticed. Plus your accent can do wonders. In Minnesota, I am considered very southern. In Texas, my midwestern accent is "cute". Ditto for Florida. (In Canada, I was considered verrry southern)
On the lighter side, I recently went to meet a business traveller. He had mistyped his room number in his message to me. I knocked at Mr. Wrong-room-number's door. Damn. I wish it had been the right one. He was 5'6" and very toned with a great smile. He was barefoot, in plaid flannel lounge pants and a tight, white t-shirt that left nothing to the imagination. Unfortunately it hid his package. He said when he opened the door he thought I was a friend from work. He had me thinking with the head in my pants, I was caught so off guard. My brains were mush. I couldn't think. I think he knew it too and was enjoying my situation.
I drooled my apology, explaining I must have been given the wrong room number by my friend. I left him standing in the hall, outside his door. When I got outside and blood reached my brain again, I knew I had blown a real chance. I should have turned around, flashed him a smile, and asked to use his phone to call my friend, offer to polish the light bulbs in his room or sort the ice cubes in his ice bucket. Something-- Anything-- to be able to keep checking him out and maybe close the deal.