i bought one of HF blast-in-a-buckets kits a while back.
not expecting much out of it, i was not disappointed.
for rust they work fair. for paint not so good at all.
these are very similar to what you find in most blast cabinets.
i used mine mostly to clean up my frame before i painted it.
for this it worked very well, getting in all the nooks and brackets.
don't expect much from it and you too will not be disappointed.