You said to not recommend a "product" - however, I've seen testimonials about castor oil application removing stretch marks.  CO is cheap, and you can find it lots of places.  Be aware though, it is tougher than the dickens to get it off of your skin and almost impossible to remove from clothing, etc.  A CO pack may help too.

Ingesting my urine has remove "pre" cancers (before and after has been dermatologist verified).  It took almost a year of daily ingestion.  This was after topical application of urine did nothing for them.