s that have used strap-ons....?

Ok so me and my girlfriend just bought a new toy(strap-on) today. First time ever using a strap-on and I was wondering..... what can i do to keep it from getting so dry, lubricants? annnd is it ok to use the same strap-on with your partner, if its washed with soap and warm water? Oh and 1 more thing... It has a vibrating tip and the rest of it hollow so it collapses once goes so far, considering my partner is a virgin it makes it a bit difficult! thank you in advance for any advice you might have! =D its greatly appreciated!