> Maybe deleting the native apps and using the webapps will raise the barrier to entry high enough that I'll only use them when there's actually something I want to do on them.

+1. I have found that switching to the Dillo web browser (with CSS and at times even images disabled) has considerably decreased the time I spend on Facebook. There was also a command line client for FB, but iirc it's not maintained any more.

So, yes, use an "ugly" browser and you're good. :-)