Clean properly dirty ashtray
You know that: You're celebrating a party and the ashtray is fuller than the big garbage bin in the kitchen, and stuff that you did not even think you'd ever land there.
But that's no problem for us: oven cleaner is the solution!
So you can conveniently spray the ashtray from the inside. The ingenious thing is that the stuff foams up completely, which means you can fill every nook and cranny as well. Leave the foam to soak for about 20 minutes (or follow instructions on the package). In most cases, you can simply rinse the ashtray with clean, hot water. In cases of hardship, you may have to rerout briefly with a brush (but please do not use the dishwashing brush).
But please take a look at the tin beforehand - unfortunately you can not use it on all types of material.
