I just tried the bbq starter on some masking tape, it seems to dissolve the glue. I'll have to wait until tomorrow to try it in my lighters.
£3.50 for one litre from Lidl, label says:
Contains:hydrocarbons, C10-C13, n-alkanes, isoalkanes, cycloalkanes,<2% aromatics, EC no 918-481-9
Lighter fluid, 100ml for £1 (£10 per litre) from poundshop, or was, not sure about now.
Contains: Solvent naptha (petroleum) light aliph, EC no 920-750-0