Hi Joe,
In my experience it's not possible to add an effect to just one or two notes, the effect would have to be added to a channel.
Probably assigning the snare notes to a separate channel and applying an insertion effect to that channel would be the only way.
As I recall it requires three SysEx messages.
1. Select the effect type.
2. Set the level.
3. Assign the effect to the appropriate part.
That's just a quick summary.
JohnG.