Yes, my Stel square wave set only uses HF for ignition on AC,
still not likely to work with a supermarket buzz box though is it.
i have been reading this with interest and will try and clear some things up as it is getting a bit confusing.
1st of all modern AC/DC tig sets can often weld ali WITHOUT ANY HF at all. my miller dynasty can operate on lift tig with no hf or i can use hf start if where i am welding permits it. hospitals and airports dont let you use HF.
2nd the oil cooled AC stick sets CAN be used for welding ali but you will need a HF box i found one on fleabay for around 60 quid second hand once! run 2 leads from the set to the HF box then out comes earth and the torch.
do you know you can also buy aluminium stick rods for stick welding? if you dont need the work to be overly neat you can use the sticks (best if you can get it downhand, but vertical up goes really nice also)