Whirlcool, it could be the water in your new area, but again as you say it could also the keeping the machines in a cupboard.
DaDoes,
Don't honestly know if "spray" washing/rinsing would work, spray household surfaces with a vinegar mixture to clean/control mold all the time and that seems to work though.
All one really needs is water hot enough to loosen and carry away the grime. Whatever coming out of your hot water heater is fine. Hot to boiling water will help kill off the nasties though, so many with washers that have heaters set the machine to 140F to 180F, or even boiling. Am not too thrilled with the idea of boiling water and mild acids (vinegar) so only use tap water.
The vinegar and baking soda works very well in particular for high end European washing machines like Miele's that have strong restrictions on using chlorine bleach.
Lysol (in the brown bottle).
Only tried that once and am here to tell that was the only time will ever launder anything in Lysol. Damn stuff left the laundry and washing machine reeking for ages, and the scent never really quite left the washer. Rubber and plastic parts in particular seemed to have an affinity for the Lysol scent.
Years ago Lysol used to sell a product called "laundry sanitiser". Never bothered to see what was in it and how it worked; sadly the product has long since been discontinued.
Problem with mould in washers is more pronounced in front loaders, and especially those in certian parts of the UK and Europe due to the quality of water. Mould and mildew need moist,warm places to thrive, and a shut up front loader provides the perfect incubator for mold. More so if the unit is not run daily and or washing is done mostly in warmish to cold water.
Undissloved detergent, detergent residue, human skin residue, soils residue, fabric softener residue and so on all provide great food for mould/mildew. If anyone really wishes to be grossed out, take a look at the "outside" of a front loader's drum and rubber boot. This is the side between the inner tub and outer tub. There one can see ages of gunk,mould, hair and god only knows what plastered to the side of the drum.
L.