Can you buy TFR in shops?

I’m looking to get some to dilute heavily and use for a pre-rinse for my engine and wheels. I’d like to get it ahead of ford fair so buying online is a now (and delivery is expensive for liquids in bulk quantitys).

Where can I walk in and buy some off the shelf, will nip to my local motor factors but its unlikely they have it, and don’t know if halfords stock it?

Any help guys