Best way to clean reusable pads

Hi everyone! This is my first time posting in this sub, and although there are other subs specifically about reusable menstrual pads, I wanted to ask here because this is more about limiting my waste. For context, I have purchased my first ever set of reusable cotton pads and they're wonderful so far, literally in my first week. I get very heavy periods and they last usually the full week (yay me) so you can imagine how many pads I would have to go through every time I get it. Because I didn't want to continue using disposable ones, I got a set of 4 cotton pads, and I'm working my way through them.

I have a few questions regarding cleaning, and please bear with me as some of these questions might seem dumb, but I really want to do this in a clean, responsible way:

1. What do you do with the pad you are changing in the moment you are changing it? Normally, with a disposable, you toss it in the trash and put on the new one. For my first cotton pad of the week, I changed it, got in the shower, rinsed off the blood, and let it air dry. I know its not fully clean as it needs to be so I plan to wash it later with the rest of them. But as I go onto my second and third ones, I'm running out of places to just leave it. I don't live alone and while its not an issue for them to be around, I prefer to have it in an organized location for later.

2. Is there a spot you keep them while you wait to wash? Is that even a thing? I ask because obviously with dirty clothes we use a hamper, laundry basket etc. But this is obviously something soiled so tossing them into the dirty laundry for a few days is not an option.

3. I'm worried about using too much water. At what point do you toss them in the wash? One at a time feels wasteful, especially given the world's situation right now, but waiting to wash them all at the end might be unhygienic and cause them to develop a smell.

I have a washer and dryer in my building and I try to not do too many small loads unless necessary so access to a washer isn't an issue. I would love any and all advice on this topic! Really love using them so far but given how heavy and how long my periods are, I just want to make sure I'm balancing being clean and being conscious of my water usage. Thanks!