I have to disagree about the Water base lube being "inert" as far as the Human body is concerned.
Arsenic solution is water based as well. (no pun intended)
Doesn't make it inert, other than LACK of inertia after imbibing !
The Carriers and additives in pretty much all Bathroom products are the problem.
Check out the Material Data Sheet for Sodium Lauryl Sulphate. This is probably the main Carrier/bulking agent in cosmetics, shampoo, toothpaste etc.
A "known" skin irritant and commonly used as a base line in Allergen testing.
Am just looking at the ingredients in a bottle of Astroglide. Sheez, a chemical cornucopia of Carcinogens.
Methyl Paraben? hasn't that been banned in Sunblock?
There are some great "Organic" water based lubes available now at Health Stores. The problem is the expense.
Basically, I think of it this way, If I would'nt eat it, then why would I stick it up my Butt ?
Answer, 'cause it's fun !
Bottoms up.