I have used both Saphir Reno and Venetian shoe cream on my natural CXL boots. Both worked well. CXL doesn't really need much care. There's so much oil in them that all that's probably needed is good brushing or maybe a damp cloth if they get dirty. Every so often, a treatment with Reno or VSC for moisture and conditioning and you're good to go.
I usually use venetian but I tried some Kiwi saddle soap for some cleaning this past weekend. Did a nice job. Nothing beats Saphir Reno, IMO. Just the smell is good enough for me.