I think it would be better to avoid unnatural chemicals, whenever possible. In theory at least: each--a man and a woman both--should naturally lubricate. Just stimulate her a lot first to whatever degree necessary. You don't want to injure her, OR get her sick from substances that shouldn't ordinarily be absorbed.
Slow seduction is really part of the fun anyhow. And indeed, my own fantasy would be: that while she's walking up the stairs, I should give my lady a nice impromptu kiss on her bottom.
Undoubtedly, if she's pleased, she'll let you know. And in that event: pussy kisses and nuzzles should follow.