I went to DCHS for the first time on Labor Day 2008, so my experience is very recent. After experimenting a little bit with days, times, entry points, times of the year, here is what works best for me, to achieve the aim of a relaxing, trouble free visit to DCHS with less of a crowd: Weekdays are generally better than weekends, early mornings or very late afternoon/evenings are best in the summer, cold weather is better than warm, especially when the creek water is really cold (it scares people away from crossing the creek so fewer go), Winter/Fall/early Spring better than late Spring/Summer, Bradford Ridge trail is preferred point of entry (the drive to this trailhead is much better than the other side and quicker from Los Angeles, there are few cars that use the road) but Bowen Ranch would also provide about the same level of safety for a car. When the weather is warm, anytime after 10am on a weekend is unpredictable. It just depends on the attitude of who shows up and how many people there are.
The majority of people will be textile, but nudity is common, both on trails and at the springs and almost everyone is tolerant.
I have been an outdoors person all my life and I grew up in a rural area with very few people, so my tolerance of crowds in the outdoors, especially those who have little understanding or respect for nature, is pretty low. But, just based on my experience of the past year I still think this is one of the best places to go, naked or not, in the Southern California area.