What kind of cloth is OK for cooking glutinous rice and how to handle it

There are indeed different varieties of sorrel,* but they're both/all high (though I can't determine how high) in the substance of concern, which is oxalic acid. This acid is found in lots of other green leafy vegetables, notably spinach and parsley, and is the reason that you shouldn't eat rhubarb leaves.**

It seems to have a reasonably high expected lethal dose; the internet echo chamber puts it at 600 mg/kg, which would mean eating pounds and pounds of whatever leaf you've got. The necessary amount to cause sickness is obviously much lower, however. There's also a long-term risk for kidney stones -- oxalic acid combines or reacts with calcium to form calcium oxalate, which is a major component of those stones (and this is the mechanism for more immediate poisoning, whether lethal or not). I have also seen reports of simple mouth and digestive irritation, again caused by the calcium salt.

Unfortunately, it seems that cooking does not destroy oxalic acid. It may be possible to reduce its presence by boiling and discarding the water, however. It's unclear to me whether this is because the acid itself dissolves into the water, or whether the oxalates (Harold McGee says that the potassium and sodium salts are water-soluble) form during cooking and are dissolved.

In all, I think the only recommendation that can be made is simple moderation. It's incredibly unlikely that you'll kill anyone with a salad, but don't eat the stuff in large amounts every day.

*"Common" (looks like elongated spinach) and "wood" (looks a bit like clover, but the leaves are cardiod) are the two that I'm most familiar with.

**Although it seems that there's possibly at least one other poisonous substance in the leaves.

There are several aspects to this:

• first, consider the meat. Chicken from the supermarket, ground beef, or a piece of steak? Chicken is more likely to be contaminated - I treat anything that has touched raw chicken as contaminated and do not reuse it. A steak I am a little less worried about, partly because I like my steaks well seared on the outside so they are hotter on the outside towards the end of cooking than other meats.
• second, do you have to use tongs to put it in the pan? I often use my hands and then wash them, and only start using the tongs once I'm dealing with hot (cooked on the outside) meat. Same for burgers: I don't put them in the pan with the flipper, it gets involved when they're ready to turn for the first time
• third, consider that if some bacteria did get onto the tongs, after 10 or so minutes on the counter while the meat cooks, that bacteria would not have grown considerably, not all of it would then get on the meat when you reused the tongs, of those that did reach the meat, some would be killed in the remainder of the cook time or just from contact with the hot meat surface, and after 5 or 10 minutes of resting whatever remained would not have a significant growth. Compare to picking up yesterday's raw-chicken tongs from the counter where they've sat for 23 hours and using them to handle today's rare steak. That would be nasty.

My rule is to minimize reuse of utensils, but I don't have 10 pairs of tongs and someone to wash them for me, so for some meals it happens, and as long as it's not chicken, I don't worry about it.