OP bear in mind that, at the beginning of your thread you hadn't really considered all the implications of ldc's and your main concern was that he might have had a personal dance. Now you have started to think it through, you are coming to the realisation that there is a lot more to the sex industry than just how it affects you.
Your dh might not be in the same place, he also might not have really thought about it and you clearly have not discussed it as a couple. My dh hates the exploitation and abuse of women just as much as I do so we are agreed that neither of us would want anything to do with ldc's and neither of us would go to one, works do, stag do, whatever. This is the sort of conversation you need to have with him.
There's not point being angry or upset with him if he thought he was doing something with your blessing. You need to explain that it's no longer acceptable for you. If he won't stop going then you have a deeper problem which will be harder to sort out but not impossible.
You can find out a lot more and if you are interested post or lurk on some of the feminism pages.
When was the corporate event? I ask because if it was last week, he might be reimbursed but if it was a long time ago, he probably won't. That would mean that he isn't bothering to claim it because either a) the company do not approve/condone of ldc's and won't pay for them or b) it was private for himself, not related to the company.