To improve circulation i use to walk up & down a lane of our local [warm water] swimming pool 3 times a week,[ its non weight bearing ] so there's no pressure on your feet like normal walking on a pavement and i always got there early when they first opened [ 6.00 am ], as did a lot of other people all doing the same thing for all differant med problems, really gets the old pump [ heart] going and doesn't hurt your feet at all.
I found that going early you miss all the other swimmers that use all the pool, like loads of school kids anything from 9 am onwards is a good time not to be there trying use to one lane.