"...but heard that i can use cheap ingredients from home to get it straight. is this true?"
"...i really dont want my hair to cause a big fuss for me while im on holiday"
While I don't know if there are products that can
probably do it very cheaply, I think you have to ask yourself a few questions first.
Are you prepared for the possibility of a hair disaster? Would having a complete hair disaster ruin the two weeks? If some of your hair breaks and comes out in batches, will it upset you? Are you willing to color your hair to fix any color change that may occur as a result of your attempts at straightening?
All of the above results are definitely a possibility, and have happened to more than a few people who decided to save a few dollars by putting chemicals on their own hair to straighten it. (Sometimes, it happen even when a professional does it, but that happens far less often.) Wouldn't a new, shorter hair style help alleviate the potential frizzing problem? Spending 30 minutes or so every day fixing your hair is much less time than spending all two weeks of your planned celebration miserable because your hair looks like your were in a chemical explosion.
If you really feel it is necessary to do something with your hair, spend a little less on your trip and pay to have a professional take care of your hair.