Seasonal, No Sewer Hookup, What to Do With Black Tank

I use a blue Barker 30 gallon tote tank to empty my grey tanks. I do not use it for the black tank (personal choice).

The grey tanks must be emptied every 2-3 days since we don't do a good job of conserving water. The blue boy works great for this.

The black tank takes much longer to fill up. At most we would need to empty it once a week. For this I would prefer to hitch up and take the 5er to the dump station. I know it would be much easier to use the blue boy, but I don't like the idea of black water in it.