I only wash my filter bag occasionally. Mainly I use the method recommended by CarlD (I believe). Fill a bucket (I use a 3 gallon paint bucket from HD). Turn the filter inside out. Rinse repeatedly. Toss water and refill. Rinse and wring filter. Let air dry inside out. Works great.

My Rover plus does go straight first, then curves, then straight/curve and so on. In one direction, it should go straight, in the other, it should curve. It sounds like you may not be putting the pin in the front (it should be moved from side to side every run or so to even out twists in the cord).