My red has many fruits. White has not flowered.
How are white variety going to help with cross pollination?
If you have a red fleshed variety and a white fleshed variety, they should have no problem pollinating each other, as long as they flower at the same time, Or at least close to each other. It’s pretty simple - if they’re not the same variety, the pollen will work.
Growing dragonfruit is pretty simple, if you have 2 different flowers at the same time, and you lend a hand to pollinate, you will get fruit.
If they don’t flower at the same time, you need to save pollen for when the other variety flowers. I have over 45 varieties and sometimes things don’t go right, no different pollen , and so I end up with no fruit!