Type 6 License

I am curious to know what those of you with Type 6 Licenses do in order to purify your distillate. I’ve always done carbon/wyo scrubs and saline washes using Heptane. However, Heptane is a hydrocarbon and so it seems you can’t use it in a Type 6 licensed facility. What other options are there?

Have you tried substituting a terpene, like limonene?