textutils.slowWrite()

Is there a way to do textutils,slowWrite() on a monitor?

You can redirect to the monitor. Then it'll print there, instead of your terminal.

You can use

monitor = periphheral.wrap(side)
oldTerm = term.redirect(monitor)

where side is the side of your monitor. Or to save on memory

oldTerm = term.redirect(peripheral.wrap(side))

If you do either of these, just typing textutils.slowWrite(text) will print it on the monitor. If you want to be able to use the computers terminal again, you can redirec to the oldTerm table.
If you want to use both the monitor's and computer's terminals often without having to redirect it every time you need to use textutils.slowWrite() on the monitor you will have to write your own function to slowWrite on the monitor.