I’m not sure what the problem. While we occassionaly have a *pop* (and splatter) from one of the lights when they go out, they don’t happen very often. Far more oil gets on the leichter and tray from my spilling the oil while filling up the cups in the first place.
FWIW, we use large cups (not the small ones that are used with Channukah menorahs). We fill the cups to about 1/2 – 2/3 of the way with water. The rest is oil.
The Wolf