Pretty sound advice.  I know some years ago my PT had told me that tendons do not get the blood supply that muscles do so they take longer to heal.  This process you explain makes sense because it would help get a little more blood to those areas.

My injuries have all seemed to be related to tendons and take a while to heal.  But again, this is good advice.  I have already been getting in to the heel and surrounding areas with my fingers but I imagine a lacrosse ball or similar would work better.

I've never had it get bad on me, but fwiw I swear by just getting on top of a lacrosse ball with the areas up and downstream of the problem... think about where that tendon attaches/inserts and work the areas close to those points rather than where it's tender, just 5-10 mins at a time. Usually takes a couple of days to make significant change if you're at the point where you're having a problem. Hunt around a little, find the tough spots and work across them.. if that's too much just hang out there and contract/relax into them. If that's the issue and you can ease the tightness in the soft tissue, the problem might just disappear. No promises, but I've gotten an awful lot of mileage out of this. My best friend is an old green lacrosse ball...