I've used the Innisfree Super Volcanic Pore Clay Mask, which is similar to the vanilla version but with AHAs added. It's a good, reliable product. Goes really solid, and you can't feel the 'pulsing' effect you get with some masks. It's not too tricky to get off and did definitely seem to shrink my pores immediately (I did an oil cleanse after, and I did get plenty of grits).
Sample packets of the clay masks are easy to come by, and the packs are a generous size, too (two masks from one pack, I find). It really is worth trying out.
By the way - the Innisfree mask instructions recommend using a toner first 'to even skin texture'. I put on some Cosrx 96 Snail Mucin and let it soak in before I used the Innisfree mask - I think this helps keep it from being too drying. You should be oil cleansing after a clay mask, and it may be a good idea to just dab off the excess oil, letting it sink into your skin as an occlusive, rather than washing it off with a foaming cleanser.