Will this work?

[diveongas]

Your answer makes no sense at all. You are saying that the ONLY solution is to "just buy a drysuit" .... funny, I see people diving with sms 75's and wetsuits every weekend. I passed my cave class in a wetsuit. You are saying that nobody should be in a cave without a drysuit? reallllly?

Unless you have a dual bladder BCD, I would say to you, that you should not be in a cave with a wet suit. I would further say that if you plan to use a drysuit for back-up buoyancy, you'll need gaitors (spats) and keepers to keep from blowing your fins off.

[diveongas]

This brings up a serious issue though,

My buddy dives double 104's and he has a dual bladder.

I dive a 3 mil wetsuit and LP 85's, with an SMS 75.

They don't make a dual bladder for the 75.

I've wondered what happens if I'm 1000 feet back in peacock and have a bladder failure... Crawling out would be a MESS.

"JUST BUY A DRY SUIT" is not really an option. I don't want to dive dry. I really don't want to spend two grand on it either.

Shouldn't I have some sort of plan in case of bladder failure? This looks like a viable solution.

Seems like you've already decided on a plan that involves saving money at the expense of safety.