I hear you. We have just been through a month of DS being so uncomfy from his teeth and waking constantly.

He also spits out panadol but what we do is give him a squirt in his mouth and then hold a dummy in his mouth. His immediate reaction is to suck and therefore swallow. If you don't use a dummy I guess you could try a finger.

HTH
Spring

ETA: BTW I think a patch is a fantastic idea.