Decomposition? (Details inside)

A rat (Rattus rattus) has decided to expire in my wall. The smell has gotten progressively worse for the last three days. Unfortunately it is in a bathroom wall so I can’t just stay out.

Scented candles and incense mask it for short periods of time. Since I am not going to tear into the wall and eliminate the source does anyone have a suggestion for covering up the smell?

From those who have experience with this kind of thing, how long does it take for a rat to either dessicate or decompose?

How much longer must I suffer? When, oh when, will I once again have an odor free toilet (at least until I use it)?