Do not wash flameproof fabrics in boiling water or with bleach. Wash in cool water, and rinse well. Always use a detergent when washing flameproof garments. If you accidentally wash them in soap, rewash in detergent to restore flame retardency.
Use cool water for any flameproofed flannel items such as pajamas. Sometimes new flannel sheets and pillowcases shed fluff. Until the problem goes away- it normally does after several washings- let the sheets and pillowcases drip dry instead of running them through the spin dry cycle. This won’t totally eliminate shedding, but it will reduce it.
Flushing requires using enough liquid to flow through the fabric and carry away a stain or the spotting agent used to remove a stain. You can use a squeeze bottle, spray bottle or even an eyedropper to flush. The key is to flush from the back side of the fabric. This will wash the stain back out the way it came, and prevent you from washing it deeper into the fabric. To avoid enlarging the wet area, put a pad of absorbent cloth on the stain. Some stains require running water from the faucet or even boiling water to flush them out.