Not exactly a mod just by dropping a bowl inside an ash can but it does serves some purpose. Capacity is reduced by roughly 1/4 but it's perfectly fine for me since i use lump 90% of the time. Makes cleaning the bottom of the can much easier. A quick fix also if you happen to have holes in your ash can.
I'm sure it will prolong the life of the ash can especially the painted older type which is getting more harder to find. Bowl are stainless and drops right in perfectly. Cost $1.29 at Costco.