Here is the sentence including the word.
I found that 「這う」 would be closest meaning of it but when conjugate to て-form it is 這って which is different.
I think your guess about 這う is correct, except it causative form which means "to make crawl". Normally that is 這わせて, however it seems that in some dialects せ can change to し, so you end up with はわして.
Here is one thread which discuses saying 見して instead of 見せて.
The overall tone of this line is pretty harsh, and sounds like it was said by a pretty scary guy. Here is my rough translation:
I'm going to beat you to a pulp and then make you crawl on the ground like an earthworm!