Foam Works.

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The foot pedal is an old Singer Machine one. Don't use one of the modern eletronic ones as it mich not stand the surges.
The transformer is a 12v one from a car charger, the meter was originally there and I have never removed it.
Using an mini hacksaw I attacted a piece of Nichrome wire where the blade used to be, and added a spring to keep the tension because the wire tended to sag when it got hot (Standard physics - metal expands)
The little soldering iron os perfect for making holes etc.
Let them make their way through the foam by MELTING, don't force it.