After reading this saga I'm glad I run with tubes....
Yeah, I'm kinda glad I kept the tubes in the event I give up and want to refit them
I took the tires off again today as the roll of gorilla tape I ordered arrived yesterday. They'd actually held a little pressure this time
Anyway I removed the original specialized 2bliss rim tape, cleaned it all up and went round each rim twice with gorilla tape. Then pierced a small hole so the valve stem was a press fit through the tape, dipped the valve stem o-rings in sealant and re-fitted them. There was still lots of liquid sealant in both tyres so I just popped them back on and reinflated. They both popped on to the head and sealed first time and have held pressure for an hour or so. I'll check again tomorrow but it's looking promising this time
I did notice some damage to the original rim tape around the valve stem holes of both wheels, I suspect it was leaking here. Both rims were wet with sealant under the original tape, which i presume they shouldn't be
The sealant does seem to have turned blue but a quick Google search suggests that's normal