I went to buy more Peat Moss as I thought I would need more soon. i prepared the soil medium early so I could have the soil ready by then.
I took a closer look at my general supermarket's common item "Horti Moss" and confirmed that it's suitable for VFT. Funny I interpreted wrongly the last time of partially decompose sphagnum as partially sphagnum. Well good to know I'm using the right now.
I bought a really cheap cloth protection against washing machine abuse and it worked well holding the medium during the rinse process.
Horti Moss first rinse
Perlite first rinse