Hey Priska! I put some sunflower oil in my shampoo today, thought I’d share with you
I had very little shampoo left in the bottle, so I figured it’d be a good time to try it. I poured a glug of sunflower oil in the almost empty shampoo bottle and shook it well, I was aiming for a 1:1 ratio. First thing that surprised me was the change of color of the shampoo - it’s normally a semi transparent pearly white, after mixing with the oil it was 100% opaque white, didn’t see that coming lol. I massaged it well in my roots, it did lather up ok, but wasn’t quite enough for the lengths. When I rinsed it off, I didn’t get that clean hair feeling. I couldn’t tell if it was because of the oil or because it had been awhile since my last wash, so I went for a second round. There was very little left, so I added a bit of water to the bottle to get it all out. Now that lathered up like crazy and there was plenty for the lengths too. I washed it all the way down to the ends, which I never do. I was intending to not use conditioner and just the oil shampoo as that was the original idea from the oil shampoo thread if I remembered correctly… But while my hair did feel squeaky clean, it wasn’t smooth enough to detangle safely, so I did end up using a tiny bit of conditioner for that.
I didn’t let the shampoo or conditioner sit on my hair (because I didn’t have hot water and wanted to get tf out lol). Out of the shower, I just put a little bit of hair oil on the ends, wrapped in microfiber towel for a bit, then air dried

It did dry very soft and shiny and with lovely movement down to the ends! Only downside (for me) was the crazy floof of frizz I’m not sure yet what I’ll do next time, but I’ll keep you posted