What is the ruling on using wet wipes instead of water for ghusl (ritual bath) after major ritual impurity, in cases of necessity and otherwise?

For ablution (ghusl (definition)), it is a condition that water flows over the limb; it is not sufficient to wipe with a wet cloth, even if the water is pure.

Tayammum (definition) (dry ablution) is only permissible when water is unavailable or when its use would cause harm, as Allah Almighty says: "And if you are in a state of janabah (definition), then purify yourselves. But if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and find no water, then seek pure earth and wipe over your faces and hands with it."

It is more probable that one who fears missing the prayer time due to ghusl should perform ghusl even if the time expires, and not perform tayammum to catch the time.

And Allah knows best.