Scale removers

I have noticed a few descalers available on the market, this one is marketed by Indesit. Does anyone know how effective these descalers are? Do they clear mould/bacteria from washing machines for example?

The following quote is from the Connect site:

Bob

Scale remover use one sachet every two months to remove grease & Limescale build up from your washing mchn/dishwsr
SRP: £10.15
Price: 1+ £5.71

Order Code: MER089780 (box10) In Stock

Qty: Your Ref:

It can protect all your dishwasher and washing machine appliances from the damage caused by Limescale and Detergent build-up By using 1 sachet per month, this will help remove limescale deposits and detergent build up in your appliance
Also sanitizing the dishwasher or washing machine’s internal parts, such as: Wash Tub, Internal Walls, Pipes, Trims, Wash Basket, Water Jets, Coils, Impellers, Pump, Wall Drainage Works to maximise effectiveness and hygiene, and must be used on an empty intensive wash cycle at high temperature
When used immediately with new appliances it allows for the reduction of detergent quantity by up to 1/3 and improves energy efficiency when used regularly Especially recommended for re-conditioning older washing machines and dishwashers
It is simple to use and as it only requires a once a month dose this provides excellent value for money when compared to its competitors The pack contains 10 single dose pouches for 10 months supply