Lottie avoid soil-grit at all costs, at all costs. Full of weed seeds and no goodness.
Compost is what you need, anything decomposed.
I should like to spend five minutes explaining things to the misinformed receptionist.
Homeacres garden is planted into compost, it appears to work!
My FAQs page has answers to these questions no.’s 15.16 on bed filling, & 23,24 for planting into compost.