I used the active recovery for a knot recently that felt as large as a small grapefruit. I followed up with massage and did this after a light warm-up so he wasnt getting on the table cold. The results were fantasic and this was a non athlete.
For loosening see how the response goes first before changing any variables.
Does your stim have a max strength modality? Quiz the therapist to see what they are thinking and decide from there.