a lot of people I notice are given the wafer in their hand and they take it and dip it into the chalice and receive the blood that way
As a cup minister, you must try to stop communicants from intincting on their own, only a cleric can do this with the proper set up; a proper set of intinction vessels and/or a paten held under the host as it is moved from the cup to the tongue. It is debatable whether a deacon can distribute by intinction. I have a question in to our office of worship on this very question. But there is no doubt that the laity, EMHC, cannot distribute Holy Communion by intinction.
I’ve been caught off guard once where at a funeral, the guy walked up to me holding the cup, as I spoke the words, “The Blood of Christ.” He quickly dipped the host that I didn’t notice he held cupped in his hand, then quickly consumed it. I was quite surprised. There have been a few other times where I saw what the person was about to do and I stopped them without a scene, although one time I had to put my hand over the cup to block the person from dipping; then she got the message.
I have been taught that to receive by intinction one should hand the host to the minister holding the chalice who dips the Host and hands it back to the communicant.
This too should not be done. If you are taught to do this, please see your pastor about this abuse.
To the disposal of water in the situations mentioned here, there are no situations where it is permissible to put water which contains fragments or anything connected with either species of the Eucharist into the sewer. Linens need to be washed with special care no matter if Precious Blood or Sacred Body particles are visible or not. This water needs to be treated with dignity and reverence as if sacred. The sewer is no place for the sacred, the flower bed outside the church is.
There are no laws, at least just laws, that can prohibit one from properly disposing of this water, whether your church has a sacrorium or not.
As far as the OP’s question, it is a matter of personal choice whether to receive the PB or not, it’s not required. I never pass unless I am sick, and I never fear about getting sick from the cup. My energy is better spent thinking about and praying about what or Who I am receiving. Either way, the linen is a cloth of sacred use, it does not disinfect, nor can it be made to. That would bring up the risk of profanation to the Eucharist. Bishops would stop the practice of offering Communion under both kinds before taking that chance. It is not required to offer both, it is optional.