To avoid or at least minimize the risk of leaving DNA tracks it is necessary to use new gloves, mouthguard, Hairnet or even better closed headcovering (e.g. bathing cap) and washed clothes with long sleeves and trouser legs. However, usually all the other People leave traces as well, means that on more or less public places it won‘t be enough of the cops to simply sweep the mixed dirt – also frequently touched things lead sometimes to mixed traces which can‘t be evaluated. But to rely on this can be dangerous: In some cases they make extensive analyses, and if your DNA is found between many others, it‘s still there.
Often they find DNA on the fibers of clothes. Also places where people did piss can be interesting for the cops. Very famous are the thrown away cigarettes and saliva remains on stamps and envelops. Also famous, but less interesting is the hair, it‘s only valid for DNA analysis if the root of the hair remains. Not helpful to confuse the cops is the DNA of non-human beings. But a specific dog can be identified through DNA what could be a hint for the cops.
At the most, DNA traces can be wiped away through disinfection on very smooth surfaces, and also only when there’s no cracks or anything. Tools on the other hand, Paper, textiles or other Objects with rough surfaces are practically impossible to clean, neither of human, nor of animal or vegetable DNA (also this DNA may be relevant).
DNA is an amazingly stable molecule. Therefore also a chemical removal of DNA traces is difficult, especially since it‘s not enough what last for sterilization (for example a simple heating or alcohol). You must smash the STRs, and they are small. Experience has shown that Natriumhypochlorit (sodium hypochlorite) works quite well, but it‘s not that easy to get. An alternative is bleaching or aggressive cleaning products, which contains sodium hypochlorite. Trade names are Dan Klorix or mold remover with active chlorine or Clorox (American product).
Hypochlorite is not very stable, it is therefore recommended that you always use a new bottle. It stinks, just like chlorine, and is aggressive towards many materials, therefore take care where you use it, for example use work surfaces like a Bathtub, use intact rubber gloves and possibly even safety glasses. Take care! Do not use other cleaners together and make sure that you cleaned all grooves and cracks with it.
In the specialized trade for laboratory there are also other products to destroy DNA such as DNA-Exitusplus or DNA-ZAP (life technologies).
According to published studies they are not more effective than ten percent bleach. Hydrochloric acid based cleaners aren‘t working that well. Heating for some time at 250 degrees Celsius in the Oven destroys the DNA (from metal objects for example). What is no longer needed is most safely destroyed through burning it.