soak an iontophoresis pad (like a big gooey bandaid) with acetic acid (the stuff in vinegar) slap if on the heel, and run an electric current thru the pad and then out a grounding pad with no acetic acid.

The current drives the acetic acid thru the skin and into the area around the heel spur, where the acidity helps to disolve the spur.

It doesn't get rid of the spur, and it doesn't stop whatever structural or functional issues are causing the spur, but I've seen it decrease the severity of spurs enough that with PT and shoe adjustments the patients could avoid surgery.

It doesn't work for everyone, but it does work for some.