Simperica works for my dogs. It’s a pill. It can be bought online without going to a vet. That’s not what you asked, but thought it might be helpful.
This. Bifen eliminates ticks, fleas, termites, and fire ants for about three months. I swear it even curtails mosquitoes for awhile.Can't speak to seresto, but try spraying your yard with Bifen IT and I guarantee that the ticks will be gone.
I buy through the vet, or did until my vet quit carrying it, now through chewy with vet approval. I just assumed the OP was trying to get something without going to a vet since he was using collars. May have been a wrong assumption anyway.