The only reason you shouldn't use jacuzzu's is because the water is too hot and this can be bad for both you and baby. Although, you are okay if you only go in for a couple of minutes, and don't get too hot.
Foot spa's are therefore fine as long as you don't get them too hot. I have a pedicure every 2 weeks (my treat to myself cause I can no longer reach my toenails to paint them!!), and the salon I go to specialises in treatments for pregnant women. After removing my nail polish, and exfoliating my feet, she always leaves me for 10 minutes with my feet in the footspa. and it's lurrrrvvllyy!!!!
Enjoy it Budge!