Fabric softener seems like a laundry essential. It smells nice and makes laundry soft. But once you know how it works, you may see it a little differently.
Most softeners work by coating the surface of the fibre with a very thin, oily layer. The fibres slide past each other without friction, and that is where the feeling of softness comes from. The problem is that the same layer also repels water. On towels, microfibre cleaning cloths and sportswear, this stops the product from doing its real job. It builds up a little more with every wash. After a while you end up with towels that do not absorb, T-shirts that hold sweat and strange, lingering smells.
Limited, occasional use on bed linen may not cause much trouble. But we recommend keeping towels away from softener altogether. It is healthier to get softness from correct washing, good shaking and preventing limescale. And then there is the question of scent: clean laundry should really smell of nothing. Heavy perfume sometimes covers a smell rather than removing it.