Anything that increases the circulation to the area will also help to disperse the haematoma.
Try getting buckets of hot and cold water, and using a sponge or flannel, hold first the cold then the hot flannel onto the area. I'd do that for about 15 - 20 mins in total.
Movement will also help to improve the circulation, so walk in hand if it can't be ridden, and try gently massaging the area.
Haematomas can take a long time to disappear completely though...
S
I just used to plonk a blob on morning and night of the Ibruleve and in about 2 days it vanished. It was one of my vets who suggested it rather than using the expensive Tensolvet
My old girl had a large one on her chest from a kick and i just massaged it when ever i had 5 mins to spare and kept putting cold flannels on it, it went in about 2-3 days
Hot and cold fomenting, holding hot cloths against the haematoma increases the blood flow that collects the junk, then cold cloth reduces the blood flow so that the area doesn't fill again. Needs to be repeated at least twice a day - preferably more often.
If it becomes hard or lumpy then ask the vet to lance it, they do sometimes become infected and are gross - I'm not usually squemish but when the boss lanced a large haematoma on one of the racehorses the stuff that came made me feel really ill.