Sounds a bit like Russian Roulette to me! Then again, it could 'spice things up a bit'. Perhaps replace the filling with extra spermicide/STD killing fluid. Or some kind of silicon gel filling with tiny beads suspended in it may increase sensations. Your menthol/chilli idea could easily be tested at home by simply using 2 condoms. That would be the easy part. Two willing volunteers may be harder to find ;-)

Surely menthol will make partners cling to each other and giving them a false sense that they have reached a high level of orgasm, when in actual fact they will be riding in the Danger Zone

Or better yet, the stuff they make glowsticks with.

Well you would have to think about the risks involved, infections may result from the substance inside, i think just a thick condom (Available for use in anal) would work fine or doubling up may work.You should also think about the Latex, vaselene for example dissolves the latex used in condoms!

Using two condoms at once is not recommended because the friction of latex against latex increases the risk of breaking. A two layered condom would run that same risk.

Hell, I can hardly feel anything wearing just one condom! Now you want to put another one on? Nah. At some point, it might be better to risk the STD, instead of walking around with Tabasco dick.

Condoms...chili...talk about kickin' it up a knotch. Why not just throw in some oyster crackers and, like AC/DC said, make a meal out of it. BAM!!