Probably the most popular method for charging a chaos magic sigil is masturbation, it's very likely the most widespread use of sex for magical purposes. Being such an intimate issue, people have different attitudes towards sex, and I feel that any hangups can have an adverse effect on your magic. Unwanted thoughts like "I shouldn't be doing this" could interfere with the process. Some practitioners may not be comfortable with sex and prefer other methods instead. Additionally, I'd say sex magic isn't equally well suited for every purpose. For example, I would think twice about powering a curse by means of sex, it just would feel too weird.
You're right that psychological comfort and integration matter a lot. If someone is carrying shame, guilt, or internal conflict around sex, that tension usually leaks into the working and muddies the result. For a lot of people, especially early on, forcing sexual methods when they're not genuinely aligned can do more harm than good.
That said, I think reducing sex magick down to “masturbation as a charging method for sigils” misses most of its depth and danger. In the Thelemic and Babalon current especially, sexual energy isn’t just a battery you top up. It’s a current that can dissolve boundaries, open gateways, and create very real shifts in both the practitioner and the field they’re working in. Using it casually or mechanically (especially for things like cursing) often backfires precisely because the force being invoked doesn’t care about your surface intention — it responds to the whole state of the operator.
Different kinds of workings also call for different energetic approaches. Some things are better served by other methods entirely (breath, blood, art, invocation, etc.). The “best” method is usually the one that actually matches the nature of the work and the condition of the magician, not whichever technique is currently trending in chaos magic circles. However, what you described is precisely how I charge my Solomonic talismans.