The fun never ends: 2002 Sonata GLS slow leak in A/C somehwere. Is it worth using stop-leak stuff?

A while back I posted that I recently discovered my A/C doesn't turn on. Apparently due to my freon having leaked out. So my mechanic says
I have a slow leak somewhere. He checked all the accessible lines and it doesn't appear to be on the outside. He said this leaves the inside under the dash. Fun fun fun. So he says there's this new stuff on the market that might help stop the leak if it's introduced into the system. Anyone have and experience or luck with this stuff? Is getting at the A/C stuff in the dash (condenser et al?) easy or does it require the dash to come off and 20hrs of labor? Just checking my options in case this stop-leak stuff he's going to try doesn't work. Thanks for any replies.
- Thee Chicago Wolf [MVP]
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.