I know with other types of concentrate you can use a steel pad, ceramic stone or organic cotton to vape them in a herb vape so that might work, but I have zero experience or knowledge with old school hash.
Gosh, this makes me think Dynavap even more.
I don't know about old school hash but with herb, that's exactly how I use mine.
Heat it up, take a few hits over the span of 5-10 seconds. Repeat a few times if necessary.
An induction heater might be good for you.
I should probably stop talking...
Hopefully you don't dislike my answer, but after seeing many people ask about what vape to use for European style hash, by far and away the most common answer given is the Dynavap.