Clen off cycle is fine, but I would not use T3 until you are on gear. T3 can be very catabolic and break down muscle tissue, especially when the dose is higher.  Even on gear, I would keep the dose lower. Use it to suppliment your diet and cardio. This way, you can remain full and strong. You'll find that when you take a lot of T3, your muscles arent as effective in the gym and it can be very hard to get a pump. I'd go no higher than 50mcg and i would work my way up to that, over wks.