Currently I am working on lacing my first hub motor wheel (2x) and am revisiting the subject of spoke prep. I have used 'rock n roll nipple cream' in the past but lately have gathered this may be unnecessary. Reason being is that this approach along with boiled linseed oil, threadlocker function to lock the nipple in place upon curing. This may be the preferred result of someone who is building a wheel for someone else and would like to minimize subsequent maintenance. However, if one is building their own wheel, it could actually be preferable not having the nipples locked in place. That is because the inevitability of maintenance will ultimately be less difficult if a non-hardening lubricant is used.
It may be true that a professionally built wheel, if used as intended, should not require any kind of periodic maintenance. There may also be concern that a simple lubricant such as chain oil or waterproof grease would invite nipple movement. However, many a properly-built wheel that employ non-locking spoke dressing do not loosen overtime, at least considering standard 3-cross lacing. Therefore, someone who may only build a wheel now and then may find it helpful to retain the possibility of fine-tuning the spokes over time without fighting a locking spoke compound. I believe in this way, a wheel will retain a more handmade and personal status.
After reading many differing opinions on this subject, may I say debate, it became clear this is a personal choice based on one's maintenance habits. Perhaps a locking spoke prep could compensate for and retain true of a imperfectly tensioned wheel. Or maybe a simple lubricant doesn't work well for a professional who would rather not see his/her wheel back after an initial break-in. In this video (see below), the wheel builder mentions soaking the nipples in oil as a simple matter of course without any drawn out theory. It became clear not everyone even considers a locking spoke prep, and it can be easy to overthink this detail.
Even so, it seemed worth asking what his impression is on using oil vs grease. On highly dished wheels, the difference in tension between the sides can be significant. Would dressing the spokes on the non-drive side with grease actually be optimal for discouraging movement in the lesser-tensioned spokes? I sent this question to them but have not heard back. For this upcoming build that is merely a front wheel, I will likely stick to oil all the way around, and yet even here there are differences. For example, are there any indications as to whether Triflow or Phil tenacious oil may best be suited?