Yes I build my own sidearm heaters to fit the tank in almost all cases, I have used plate exchangers for domestic hot water but in most cases I prefer the sidearm as it will heat the entire tank very close to the boiler temp and then I install a mixing valve on the hot water to prevent scalding and keep the water a consistant temp. as far as cleaning, all it takes is purge tees and boiler drains on the sidearm or plate exchanger then ball valves to isolate the exchanger from the rest of the system. close the ball valves, hook up wash machine hoses to a pump and flush the exchanger with calcium lime and rust remover (CLR) or a comercial coil cleaner from the supply house no need to remove the exchanger and the solution is pumped through it helping it open up faster, It usually takes about 5 minutes per side and the exchanger is as good as new