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To 3 ... Putting a sauce that can burn your mucus membrane and also often includes sugar inside a pussy is highly idiotic, unless you are really into burns and a vaginal fungal infection... Using ginger is a way safer method but even then I would advice to stay away from the inside and stay with the pussy lips and clit ... Or get something that is especially made to be used in a vagina ...
To 4 ... Really, you tell a random person to do needle play , with no training or idea of what they are doing that you know of?... Risk of an infection and permanent nerve damage causing loose of any feelings in them... If you want to do needle play you really need to get some idea what you are doing, I would advice to get into a class for needle play or technically you could also get a class about piercing for a lot of the info... Then you need to get medical grade needles ... proper disinfectant... medical cloves .... But hey you will learn that if you get what you need to do this as safe as possible and don't follow some random fantasy.
To 5 ... again something you should at least give some basic safety advice ... this is doable, but keep some things in mind , in case you need to get it off fast you really want medical safety scissors around that are flat enough at the tip so, in case, you could get under the string and cut it... "For a while" is a bit "vague" ... Don't tie it to tight, especially if you have no idea what you are doing, and stay at maybe 10 minutes at the most for first tries. That may increased a bit over time... Cutting of the blood flow into a body part completely is a lot harder than many people think ... but the nipples are a place where you could get to the point, if you go to tight. The even bigger risk is , as with clamps, to cause nerve damage. Any form of feeling a tingling sensation is a sign to stop right away, and also in that regard keep, especially first, tries on a low time.