I don't think it will work, either.
Here's some solder on copper strippers from the Metal Finishing Guidebook (free - #18 in this post - there's a digital version on metalfinishing.com).
http://goldrefiningforum.com/phpBB3/viewtopic.php?t=294
Digital version:
http://e-ditionsbyfry.com/Olive/AM3/RMF/Default.htm?href=RMF/2008/11/15
Ammonium Bifluoride.................40 oz/gal
H2O2(35%)...............................16 fl.oz/gal
Temp........................................70-90 F
Acetic Acid.................................31 fl.oz/gal
H2O2(35%)................................5 fl.oz/gal
Temp.........................................Room
Fluoboric Acid.............................16 fl.oz/gal
H2O2(35%)................................5 fl.oz/gal
Temp.........................................Room
Sodium Hydroxide solutions will dissolve tin, but there might be too much lead (40%) for the tin to leach out and powder the lead. Maybe try heating a solution of about 10-15% (weight/volume - 100-150 gm/liter). If it works, the lead will probably brush off.
Why on earth do you want to dissolve the solder?
BTW, any gold that was under the solder is now part of the solder