I'd like to try using marshmallow root powder in my HP bar soap. I'm thinking about mixing it with water and my honey and adding it last. Recipe is 25.40 oz total wt (oils wt. 16.40 oz) so I though I would start with 1/2 t. Does this sound OK (I've never used this before). I typically add silk peptide so I am assuming the marshmallow root would take the place of the silk.