I have already looked at such a thing. My copy of PGtF was sitting on that very page.

Its quite TO, but works RAW, though see below.

Some Thoughts:
1 This only works with one spell
2 It does not multiply spells, so this requires even more outside help from spellcasters to give you a spell. Otherwise if you want to be the caster, you sacrifice your spellcasting for one spell (not a good idea imo)
3 The weapon does not state that it is capable of holding more than 1 of the same type of spell. "When the wielder is next subjected" obviously should be interpreted as a limitation.
(4) This requires a familiar (just like pun-pun) or another party member. Most tricks involving these are not considered by the authors.

The crux here is whether you want to give into an interpretation that screams abuse. Its not the choice between something cool and interesting, its the choice between RAI and NI silliness.