Senna capsules instead of tea?

Hi - I am starting the cleanse tomorrow, and I really do not like hot tea, so I was dreading drinking the laxative tea every night. When I was out last night getting all my lemons and syrup, etc., I saw that the store, in addition to a few types of senna leaf tea, also had senna leaf capsules.

My questions(s) are

1) Can I take these capsules at night instead of drinking the tea?
2) How many woud I take? The capsules I saw were 450 mg.

Thanks!