I'm with Charlie, and use Kerosene in my parts washer. It's crazy how expensive it's gotten. I don't think I'd want to try diesel fuel, it's almost as expensive.
SON put Mineral Spirits in his parts washer, REALLY expensive!
I have used diesel for years. But today's seems to turn gummy after 6 months or so and now the pump is all gummed up. Got it free the first time but not this time. To be fair it was a cheap parts washer 20 plus years ago so it was probably about at the end of its life expectancy anyhow as far as the plastic housing pump was concerned.
I either need to change the fluid more often or go to something else. Everything else seems crazy for price. May end up using a power washer more?