I think a complete breakdown will do more harm than good. If there is any disease in your tank, your fish are already exposed to it, so it is going to travel with them into the newly disinfected tank anyway. Then they'll go through the added stress of the breakdown and recycle which could possibly weaken them enough that they will be more susceptible to any diseases they are carrying.
If you are determined to do this complete breakdown anyway, make sure to test your nitrates first, atleast. If nitrates are high, you need to do a series of partial water changes over a course of days to slowly acclimate them to lower nitrate levels again. Sudden introduction to a nitrate level of 0 could kill them alone.
The live in tank monitors are usually unreliable as are the dip strips. Make sure you get a kit like the one livingword26 shows where you use test tubes.
i used chlorine to clean my very first tank i used every little but i also rinsed it 4 times then dried it and repeated 3x. i would use vinager now that i know more.