I remember being covered in this stuff when I had Chicken pox as a child and never though about using it again since.
Recently I came across it in Boots and just picked up a bottle - which may I add was a bargainous £2. My skin really does well with Zinc based treatments so thought i'd try this as that is basically all it is.
After trial and error I found leaving it on for a long period of time (e.g overnight) was too drying for me. I found the best for me was to:
1) wash my face (I removed makeup previously to this)
2) apply a good amount all over the face with a cotton pad
3) leave for a few minutes then rinse off.
I don't tone as I class the calamine as a sort of toner step but I do moisturise.
It does a good job of evening out skin tone and making pores smaller - oh and most importantly dired up some spots which were taking ages to go. I think it is a good preventative measure and will SLOWLY dry up any spots. I think it is more gentle than other spot treatments but works better in the long term. May work faster if you use a zinc based facial wash too.
If the idea of using the lotion doesn't thrill you, Lush also make a soap containing calamine called Freah Farmacy.
I've tried all the DS brands; Neutrogena, Clean & Clear, Clearasil etc. and I find that none of them have done much to clear up my blemishes. Then on a whim, I saw a bottle of calamine lotion in my mom's cupboard and decided to give it a try (I was desperate at this point!) The next morning I woke up to find that I only had 2 pimples! It completely dried out and cleared up my acne overnight! No product specifically targeted for acne treatment has been able to produce these results. I am surprised that there aren't more reviews for it, as it works so well!
I noticed no reviews on just plain calamine lotion, so I thought I'd add my two cents. About two weeks ago my skin went insane, not even TTOTM. I kept developing cystic like blemishes almost every day and I had no clue why. I was desperate and bought proactiv, nothing. Tried extra strength BP, nothing. I even went so far as putting lactic acid directly on the spots which just made them raw while still being under the skin. It just kept getting worse! Of course I picked at them and then that made the problem even harder to cover up and heal. After a few days of trying everything, I tried calamine lotion, sice I have luck with zinc and it also contains clay. I put it all over my face with a cotton round, and then used a q-tip to concentrate on the bad spots. The next day my skin was much less red, especially the new spots. I did this for three nights, cleansing with noxzema first to get off my heavy duty makeup, then used witch hazel, then the calamine. The (let's count them!) 8 horrible cysts on my face plus little ones (excessively clogged pores I believe) are gone, save for two which are shrunken to barely nothing and no longer hurt. I'm doing this every single night because obviously my body is freaking out and I won't allow that to show on my face. This has been my god send. I have not experienced any drying but then again my face is very oily. This is especially good on blemishes that you've picked at. Heals them and flattens them out almost instantly. It also helps with razor burn, kp, and general redness on the face including that from acne scars (I've been experimenting).