I used to use a sock off the front of the boat years ago. It worked but was never an ideal setup. Literally a lot of extra baggage, boat control becomes more difficult, not from the aspect of maintaining a heading but being able to turn. Extra risk of tangles.
Now I just use the kicker, and if its a really slow speed required, chasing walleye vs salmon & trout I will put down the electric trolling motor turn it side ways. put down one or both electric anchors a foot or two into the water. Adjust the trim on main and kicker motor. I usually don't need this unless I am dealing with a strong tail wind, or trying to stay at or below 0.8 mph.
If you must use a bag just make sure it goes off the bow or a front cleat.