Who is making you nervous about him napping in the swing honey?
I can't say I am really familiar with what the swing is but I assume it is a safe place and have heard other mums using a swing for naps with young babies. What is it that worries you?
The sling question was really that I could see form your previous post that your 3yo was upset and needed you and that you were trying to get LO down in the crib for over an hour. A sling doesn't solve all difficulties, I just thought that if you're able to have LO on you for maybe even one nap that you could spend some time with your 3yo, even sitting, you don't have to stand and carry baby in the sling and certainly not all day long. Full on cooking is tricky with a baby stuck to your front but some mums are able to back carry, or even prepare some light lunches/snacks that are not too labour intensive. I couldn't carry DS in a sling very much for various reasons and there's no way I could back carry it's beyond me...I'm just saying some people can, do and find it very comfortable and convenient.