I actually wrote up some house rules for doing this a long while back.
Experimentation gives +(simple die + risk modifier) to the experience gain from studying vis, requires one additional pawn, and necessitates a roll on a modified Experimentation results table. The actual entries are the same, but the effects and sub-tables were modded to fit vis rather than spells.
Disaster: roll (simple die + risk modifier - perception)
0 or less: Complete Failure instead of Disaster
1-2: Experience you would gain is lost instead
3-4: Experience you would gain is lost instead, and you gain a warping point.
5-6: Explosion. Valuable possessions have a 10% chance of being destroyed, and the explosion deals +(pawns x 5) damage.
7-8: A major disaster that threatens the covenant
9-10: Gain extra warping, one point per zero on the botch dice
11+: Roll twice more on this chart
No Extraordinary Effects: self-explanatory and unchanged
Side Effect: The vis casts an interesting non-ritual spell with a level of (10 x pawns). The spell is of the same type as the vis, with the other art determined randomly. This spell bypasses any magic resistance you might have but is never immediately lethal -- if it would kill you, it deals an incapacitating wound and a single aging point in a physical characteristic of your choice instead.
No Benefit: self-explanatory and unchanged
Complete Failure: self-explanatory and unchanged. Note that the vis is still expended despite the failure.
Special or Story Event: unchanged
Discovery: roll (simple die + risk modifier)
1-4: 15 XP in Magic Theory
5-6: 15 XP in a mundane ability thematically appropriate to the Art (Medicine for Corpus, for instance)
7-9: 15 additional XP in the art
10+: Roll twice on the table, treating further 10+ as 7-9.
Modified Effect: roll (simple die + risk modifier)
1-3: Gain experience in a random Form instead, which may not be the same as the vis you studied.
4-6: Gain experience in a random Technique instead, which may not be the same as the vis you studied.
7-8: Gain a negative twilight scar without experiencing twilight
9-10: Gain a positive twilight scar without experiencing twilight
11+: Instead of expending the vis, it is transmuted to a random Form. If this would cause it to remain the same Form, it becomes a random Technique instead.
