Wet & Forget cheaper alternatives?

I am looking for effective alternatives to these products due to their large volume packaging and high price. Any suggestions for equivalent products at cheaper prices in smaller packaging (1L or less)?

Wet & Forget

Wet & Forget has a unique combination of biodegradable selective surfactants for moss, mould and lichen removal on absolutely any exterior surface. When diluted with water and applied, it immediately attacks that unsightly moss, mould and grime. Then Mother Nature takes over. The weathering process gently takes the decomposing material away bit by bit without scouring the surface it has infested. Wet & Forget is the safest, most effective way of removing moss & mould from ANY exterior surface.
Non caustic. Non acidic
No bleach. No water blasting.
No elbow grease.

Shower Witch

Bathroom cleaning magic that saves you time. Why waste time getting rid of grime?
Shower Witch takes the hard work out of cleaning your bathroom. It's simple to apply and the results are truly magical.
Best of all, it contains no aggressive chemicals, is biodegradable and actually smells like a vanilla milkshake.

Wet & Forget Indoor - Mould+Mildew Sanitising Cleaner

Wet & Forget Indoor Mould+Mildew Sanitiser Cleaner is the easiest way to kill mould and mildew! The convenient spray will clean, deodorise and sanitise in one labour saving step! Wet & Forget Indoor Mould+Mildew Sanitiser Cleaner means no scrubbing and no rinsing.
Kills: Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella, enterica, Serratia marcescens.
2L 'Ready To Use'
Kills mould & mildew and inhibits the re-growth.
Cleans, deodorizes, sanitises all in one!
Easy to use – just spray and then wipe the surface.
Bleach free formulation releases no harsh or irritating fumes.
Note: For best results, eliminate the source of your moisture problem by keeping the area dry and clean. In areas with excessive exposure to moisture and humidity, such as bathrooms Repeat treatment every 7 days or as needed if new growth appears.

http://wetandforget.com.au/products.html