Depends on ambient temps and humidity. Here in my neck of the woods I keep the dice in the bottom of the pot only, and reload every few minutes.
The more DIce you throw in the pot w/ the acetone, the more risk you have of the acetone "boiling" over.
Oh, that reminds me. I made a paper towel "spatter flap" to go over the top of the pot so that spattering acetone stays off the board and plastics. fyi.
