Hi Katy,
That's a hard one to answer without knowing what was composted to make the mix, and how old it is.
It might be made from mostly vegetable material, or maybe it's made from rotted down waste like from chickens, farms or horse stables?
So without knowing what went into it, you can't really regard it as "soil" or "potting mix" as it may not drain well, , it might have a PH not right for the the type of plants you want, or it might not be sufficiently aged and so still have the potential to harbour plant diseases.
Especially with cuttings, which are susceptible to rotting
If I were you starting out, I'd want to give my cuttings the best shot, and buy a professionally mixed potting soil that will have the right blend of earthy material and peaty mix, plus fertilizer.
My recommendation would be, to buy a bag of that, such as you can afford, and re-pot your new cuttings. If you ask at a specialist garden centre or hardware place that has experienced people, you might even find a smaller bag of material specifically for propagating plants.
As to the sack, well I never waste anything so I would ask where you got it, exactly what it was, and then we can tell you how to further improve it to maybe convert it to proper potting mix or ensure it's safe for indoor or outdoor plants.

Hi Katy, welcome to GardenWeb and house plants!

I see that you're in Canada from your profile so think I should ask first about terminology. Our friends in England use the word compost interchangeably with potting mix, so I wonder if that is what you meant also? Or did you intend the American meaning of the word compost (the finished product of decomposition?)

Alison, I agree with the reasons you've offered why one wouldn't want to put "American compost" in a pot for propagation. Also agree with finding a use for this bag of stuff, once we're sure what it is.

But I would encourage you and Katy to explore this issue a bit more if interested. Store-bought bags of potting mix (at least without some type of alteration/improvement) are not usually preferred by those who have been growing potted plants for a long time for various and numerous reasons.

In a nutshell, these soils hold onto moisture too long, and fill all of the spaces in the pot, so there are no tiny air pockets. This can cause roots to rot, especially if it's packed tightly around the roots, although it will settle itself into that condition without packing.

Container soils and water retention/movement.

I don't like what peat (the primary and most abundant ingredient in bagged potting mixes) does/how it acts in a container, and since I've stopped bringing this stuff to my house, my plants have stopped dying from "overwatering." That's all I need to know. But there are other reasons one might want to move away from peat. Peat moss ecological issues.

Hi & welcome,

I'm a regular here & at Cactus & Succulent Forum (C&S for short). Pls. remove the Jade & the Aloe from that mix as it will likely rot them. Btwn that compost being too rich for them, it'll likely hold too much water for them as well & will be a quick path to their demise.

Better to use some C&S mix w/ a lot of extra perlite, like 30-40% at least. And as to succulents, when in doubt abt watering, pls. don't water. That's the quick lesson in how not to kill succulents.

Composted material aren't usually recommended for container plants; they behave differently than plants potted directly into the ground.