Some home/generic brands are scented. Open em up in the supermarket , smell them, pick the cheapest PERCARBONATE with no scent.
PERCARBONATE IS A CLEANER use it to CLEAN your gear/fermenters, just like you would dish washing liquid or the like. If you soak overnight or longer it will remove gunk with minimum scrubbing. After CLEANING store the gear/fermenter.
THEN PRIOR TO USE, SANITISE use BLEACH to prep, I like to leave the bleach for a few days or overnight (just a 5% solution ie: 250ml in 5l of water, with a capful of white vinegar to bring the PH down and make it more effective) prior to use, at least a minimum of a few hours. Put 2L of this bleach solution in your fermenter and shake, shake, whenever you pass by, give it another shake. An hour prior to use, rinse out the bleach solution with clean tap water until you cannot smell it, hose it out a few times.
NOW THE IMPORTANT BIT----SANITISE. Use Starsan, Iodophor, Phosphoric Acid, Oxyclean, Oxybright or something NON RINSE. Put a couple of litres in the fermenter, lid on and SHAKE. Again shake when you have the opportunity and leave this for 20 minutes (you can get away with a few min, but give it the time).
BEFORE PUTTING YOUR VALUABLE WORT INTO THE FERMENTER TIP IT UPSIDE DOWN FOR 10 MIN to DRAIN as these are NON rinse Sanitisers.
REMEMBER---AFTER USE CLEAN
AFTER CLEANING---STORE TO DRY
BEFORE USE---SANITISE --- PREP WITH BLEACH AND FINISH WITH NON RINSE