That would be completely pointless and you would most definitely be wasting your money. You should almost always think of liquid carbon products as CO2 first- NOT as a disinfectant. That is why it is called liquid carbon. So adding this product once a week is as crazy an idea as injecting CO2 once a week.
The function of liquid carbon is to supplement the the CO2 availability to those plants that are able to process it. Under certain conditions, the hobbyist finds that there are limitations to the amount of gas that can be injected into the tank due to toxicity issues, for example. Adding liquid carbon increases the amount of CO2 available to the plant without adding to the amount of CO2 dissolved in the water because the product is converted to CO2 internally to the plant, not externally. Therefore, add these products on a daily basis at (or just before) lights on in exactly the same way as you add gas injection. There is no conflict between gas and liquid formats. They cooperate to improve carbon assimilation. Yes the compound is toxic to CO2 related algae and can be used to directly attack these algal forms, but it is more productive to think of this compound strictly in terms of it's effect on CO2 availability, because CO2 is what makes your plants healthy.
If you want to get rid of nasties in your tank then clean your tank the old fashion way by frequent and large water changes as well as scrubbing and removal of organic waste in the gravel, on hardscape and on all other wetted surfaces. Do not depend on gluteraldehyde as some sort of crutch or tonic.
Cheers,