My mom loved to catfish with yo-yo's and did very well with them. Different lakes have different rules on yo-yo's. Some limit the number, some prohibit them after dark, some prohibit "unattended" yo-yo's, whatever that is. Check with wildlife and fisheries.
We put in north of the interstate. Its a "private" landing where you have to leave $3.00 in a mailbox to launch there. Totally the honor system. We headed further north from there until we reached the main channel and then further north from there. I've never been on that part of the river. My friend has been going to this particular spot for years. He says the sandbars come and go each year but between three of them, he can usually find one to camp out on. We're definitely going back. Here's a link to the part of the river were on, you can work you way back to the interstate. You can't see the sandbars, looks like this was taken in the spring when the water is much higher: http://maps.google.com/maps?q=hende...8378,-91.730347&spn=0.074141,0.15398&t=h&z=13
No idea about where its legal but Cabela's sells them: Cabela's -- Slater's Automatic Polypropylene Yo Yo Fishing Reel