Place bags in full sun and turn bags every few days. Would help to add some garden soil to provide organisms to promote breakdown and cut some holes for oxygen supply into bag. This is not the best way to prepare compost. Hay is harvested grass crops that contain seed or at least most hay is. Peanut hay is an exception.
Straw results from threshing such as a grain crop.
The litter may be chemically treated and may not decompose. The odor would be offensive. There is also concern about parasitic worms in meow dung. Best to mix with other products being composted and it would be better if sawdust was aged. Worms help decompose organic matter in compost piles and in soils.