Colin you know I like hot water yeah lol believe me you need it with this sawn timber you will struggle with cold and detergent to get the green algae out of the pours,it will clean up on the main bits and look way way better but up close you’ll be able to see green specs left behind unless you go over and over it.
Hot water gets rid of it but with timber like this i still use a Ubik or degreaser to speed up the process even further.