Sandal blocking

[Misty Lucas Cma]

I just made this sandal (gotta make the other still). How do I go about blocking the sandals?

[Granny Square]

If they are acrylic, there is not much point in blocking them.  (some people 'kill' acrylic with heat, which causes it to become limp and not stretchy.  It would be better if the sandals were a little smaller than the foot,  and stretch to fit).

 

If they have natural fiber content, all I can think of is make a 'foot', maybe out of newspaper covered with plastic wrap (so the newsprint doesn't get on the yarn), dampen the sandal and block it around the foot.