I've been using range cubes for years. They sink to the bottom with very little drift, melt down in about 10 min. and the channel cats love it. Just take about 10 handfulls, scatter them all around the boat, use either punch bait or charlie blood B about a foot off the bottom and hang on. Cheap, not messy, won't smell up the boat if you drop some, and every cat you catch will be drum tight full of it.