There is a relatively easy way to do the test in a light helicopter without an AFCS. Don't move the controls (both pedal and lateral cyclic) and lean to one side (if you have passengers, get them to lean as well. Lean for a few seconds, until you get a bank angle going, and then sit upright again. What you have done is introduced a change in the balance of forces and then taken it out. The helicopter, if it has neutral spiral stability, will stay at the bank angle it had when you all sat upright.
In most light helicopters, there is no need to adjust the pedals when you roll to an angle of bank of up to 20 degrees of bank. In some, it is positively a help to take your feet lightly off the pedals as you might actually introduce some force/displacement without knowing it - pedal forces are way too light in general.