How to deal with mites? (UK)

Hi all,
The other day I noticed a small black bug on Cinnamon, literally tiny maybe 1mm across. I got it off him and squished it, and when I asked the vet about it he said to wait before doing any treatments until I saw another one.
Well, I've seen another one :O So now I want to treat him. Problem is, I have no idea where to start. I live in England, what products would be best to use? What do I do?? I really have no idea where to start :(

I've seen Callingtons Mite Spray, is that a good product to use?

Usually the treatment I've heard of is:

• 1 oz Ivermectin
• 32 oz Water
• 3-4 drops of Dawn

But I don't think the UK has access that on a cursory Google peek so...

Callington's? Reviews seem good.