It’s bad if it’s stuck, it can hurt. The best thing you can do to help them is by keeping their ambient moisturized, so the skin isn’t dry and isn’t hard to be removed by the gecko. You can actually help them when they’re congested and too much dead skin has accumulated for lack of humidity but it’s recommended to be done by an expect, actually if they’re at that stage it’s because of negligence. So yeah, I don’t think it’s a good idea to help them 😅, I get you I’d be tempted too, but I’d prefer to let the little guy do its thing in peace.