Spoons. One per ounce of hops or throw in a bunch. Simple. Free. Safe.
I use dinner spoons to weight down the hop bag. You know, those teaspoons and tablespoons you have in the kitchen drawer? They are stainless so they will not give off flavors, round so they won't slice the bag, no chance of cracking like glass, and it's one less dang thing to buy and keep track of.
You probably have a lot of spoons on hand.
If you need a mash paddle, try a really long handle spatula from a grilling set, or a big commercial SS spoon from the dollar store. Why not use what you got.