In Michigan the "right arm out" is not the proper signal for a right turn. I personally follow the conventional "left arm out for left, left arm up for right" signal conventions. It's the legally recognized method and has never presented a problem for me.
Personally I think it is more confusing for motorists to have differnet bikers using different signals.
257.648 Signals for stopping or turning; violation as civil infraction.
(1) The driver of a vehicle or bicycle upon a highway, before stopping or turning from a direct line, shall first see that the stopping or turning can be made in safety and shall give a signal as required in this section.
(2) A signal required in this section shall be given either by means of the hand and arm in the manner specified in this section, or by a mechanical or electrical signal device which conveys an intelligible signal or warning to other highway traffic, except as otherwise provided in subsection (3). When a signal is given by means of the hand and arm, the driver shall indicate his or her intention to stop or turn by extending his hand and arm from and beyond the left side of the vehicle and signal as follows:
(a) Left turn ..... hand and arm extended horizontally.
(b) Right turn ..... hand and arm extended upward.
(c) Stop or decrease speed ..... hand and arm extended downward.
(4) A person who violates this section is responsible for a civil infraction.