Sounds like they may be starting you on "Stress Loading." Here is a link to a little more info and if you google "RSD Stress Loading" you can find out more.
http://www.rsds.org/pdf/ptotbrochure_604.pdf

When I did Occupational Therapy, they tried the "scrubbing" with me, but I just could not do it. I could carry, but had to start with a small can of peaches and work up very slowly. I do still try to do some carrying as part of the therapy routine I do at home.

I can't advise you on if it will help or hurt you - I am not a doctor - but "carrying" is a fairly common PT "thing" for RSD. I don't know why it would hurt your foot if the RSD is in your hand, other than perhaps you just started out walking to much, and it had nothing to do with the weight in your hand?

I don't know about Carpel Tunnel either -- how the carrying would affect that. You might want to double check with your doctor before doing this exercise.

Just wanted to say that the carrying is a known therapy treatment for RSD.