Most of this Level is to do with chance, depending on what drops on the sides of the board.
The method used in the video examples was to drop the line blasters and have them clear the rows from the bottom.
Use the earned paint booster only when needed.
It can help if you are able to set of a column of line blasters to clear many rows at a time. The paint can be used to set this up.
Also you can try to get the line blasters so that setting one off opens another, which opens a third, and use this chain reaction to clear more board in less moves.