Cleaning the beer lines of your home draft system with a beer cleaner is vital to maintaining good flowing beer. The beer line cleaning chore should be undertaken on a regular basis. It is a good idea to clean the beer lines in between each keg change. If this seems like too much for you, then at least once every month is recommended. You will notice the results of regular beer line cleaning: keeping your beer lines fresh improves taste and prevents particles from causing over-foaming from the tap. There are basically two techniques for cleaning the lines - either you leave them hooked up, or you take them apart.
Iodophor is what has been recommended as an all-purpose cleaner, and is considered a good standby for home brewers. Iodophor is used to create a water-based solution (the ratio comes on the Iodophor bottle) in a gallon bucket of water. But today, many different types of cleaners have emerged specifically for the purpose of cleaning beer lines. These products are specially developed to remove the sediment that builds up in the lines as a result of yeast particles that cling to the insides of the beer lines.
The theory is that any little rough spot in the beer lines, the spigot, or even the glass, gives the CO2 infused into the beer a chance to escape, creating excess foam. Ideally, you want a cleaner that will take away the yeast and malt sediment without "roughing" up the plastic tube or any other part of the draft system on the inside. This is why non abrasive products are used exclusively for the purpose of cleaning beer lines.
BLC has been the standard beer line cleaner for a while now, but Power Punch 22 is a newer product that has been specifically tailored to more efficiently take away yeast residue from your beer lines with less caustic effects. Both products are biodegradable, and made especially for beer line use. No matter which beer line cleaner you use for cleaning and maintaining beer lines, the actual process for cleaning the lines will be the same.
The process goes like this: take your nozzle and hoses apart, and then let the parts soak in the Iodophor solution for ten minutes or so. Unwanted bacteria will be destroyed - and, if your Iodophor and water solution is in the correct ratio, you will not have to rinse. An additional technique is as follows: make a gallon or two of Iodophor solution and run it through your beer lines for a few minutes. At first, let the liquid flow at a slow stream.
Next, close your spigot and leave it for a few more minutes (ten minutes total should be good). Thus, the insides of your beer lines will be sanitized without the hassle of taking the whole system apart. Keep in mind that the outsides of your beer lines still have to be sanitized.
If you wish to experiment, there are other beer line cleaners and beer line cleaning kits out on the market. It is a good idea to try out the differing products that look effective to you, and decide on which works best with your home draft system.