While topical finasteride isn't widely available in the UK, there are some online options you can explore:
Zava offers finasteride online. Here's the link: Zava - Finasteride
Superdrug Online Doctor also provides finasteride. You can check it out here: Superdrug Online Doctor - Finasteride
ASDA...
Hey, for a hassle-free application that fits seamlessly into your routine, I'd recommend going for a foam-based product. It's quick, easy, and less messy than sprays or shampoos.
As for application frequency, twice a day is the way to go for optimal results. Consistency is key!