My non muslim parents often eat pork or non halal meat such as chicken and also let the dog lick the plates before theyre washed. I thought that the dish washer would remove the najis but now I know that that isnt always the case. I was wondering how to purify a plate or container that pork or other not slaughtered islamically meat was in? Should I assume all the plates are najjis because I dont know which ones?

I also have the same problem with towels. We wash the dirty towels in one load and im not sure if the towels they used are najis or not or if the washing machine would clean them properly. If you could give me some advice on how to overcome these. Im worried my salah wont be counted if I eat food thats from najis plates or use towels that are najjis. Im having a little OCD about this so inshaAllah you can help with what I should do.