Are any plug-in alternatives as effective as Feliway?

[Jurassicparka]

Hi, has anyone found any of the other brands of plug ins are as effective as Feliway? It’s so pricey! My young, sister cats spend all their time in the same rooms as each other by choice, but they do seem to have been (play) fighting more recently with a lot of tail swishing. All the diffusers we had a couple of months ago have run out.

We were recommended Pet Remedy by the rescue we got our kittens from. I’ve not used Feliway but they said it’s cheaper and more effective.

my local petshop recommended this Beaphar version as being the same just cheaper. Cat seems happier too