Melting and burning the aluminium foil is certainly a problem - the copper foil seems to withstand any amount of heating with the blowtorch, and the same piece can be used several times.

I tried to remove the copper sheet from a PCB for other purposes. Sometimes
it just goes fine, sometimes it breaks off in bits and pieces ...
Wouldn't it be easier to take a piece of solid copper wire (2 or 3mm
diameter). This kind of wire is sold at any do-it-yourself shop. Strip off
the isolation and twist the copper wire as a kind of coil arround the litz.

73, Rik  ON7YD