Get the old ones, there's a slight (2mm) taper on the new ones but it is very mild and the difference will be subtle. Save your money for lift tickets.
"What you are feeling is a base burn. The toilet bowl cleaner probably has a really high pH , and therefore must be neutralized with an acid that has a really low pH. So basically, you just need to stuff your asshole with the most acidic shit you can find, battery acid, sulfuric acid, nitric acid, whatever you can get your hands on. its gonna be a chemical showdown in your asshole today my friend."