Hi pkamargo. Fairy liquid is UK brand name for washing up soap. A consentrate that is very good a cutting through grease and grime. But I’m now trying Commer in my tank and this is a non toxic cleaner used in the motor trade to clean all parts. I’ve used it many times on my bike and car and it works real good with very little effort from me 
I’ve tried a couple of commercial watch cleaning solutions and they were ok but I get just as good results with the washing up soap, plus, I enjoy experimenting.
All the best.
Scott.