Better to buy a Blue Tote, not a home made one. Also stay away from the Thetford brand.
We've used a 35gal Thetford for 3+ years and have had no issues or accidents. The only improvement I would suggest is to include an elbow fitting for dumping, but it was not difficult/expensive to purchase the fittings I needed to complete the job.
Overall, I've been very pleased with our unit.
The hose continues to come lose on the Thetford over rough terrain and will not empty completely due to a shoddy design. The Barker Blue tote has a conventional pull valve and removable hose. It empties completely every time.