I see you posted twice and in both posts I did not see a reason for an "acid flush". An acid flush is usually only done if you are having a heating or over heating issue.
What you are doing with the hose is good for rinsing the saltwater out of the block but does little to dissolve or clean out deposits that are not allowing the engine to cool properly. Again I see no complaints in that regard.
If you just want to flush the engine out for "good house keeping" I would use vinegar and let it sit for a couple of days. The vinegar is far less aggressive and still does a good job unless the block is really plugged up and over heating.
I did one acid flush in 34 years pretty much just after I bought the boat and had over heating problems. From that time on I did a vinegar soak about every 3~4 years and never over heated.
Are you experiencing heating problems?
Dave Neptune
