From a hygeine perspective it is always advisable to wash sex toys with proper sextoy disinfectant.
From an hiv stanpoint, it is not a likely route of transmission, unless the use between two people is immediate, and particularly if any blood is present. But given that hiv does not last long outside the body, it is indeed true that once a liquid has dried, hiv virus is dead or at least unable to infect. The proteins within the virus cell burst upon drying and become useless.
However, you should be concerned with other stds from sharing sex toys so disinfect porperly before another person uses them.

The only way to ensure that you will not get infected with hiv/aids by someone that has this debilitating diesease is to abstatin from all acts of sex with them. I know it may be a hard thing to do if it is with the person you love but unless you are ready to have hiv yourself, you cannot be guarenteed safety by sharing any sex toys or even having protected sex. No of it is perfect.

Yes, you are right. Abstinence is a highly effective way of avoiding hiv.
However, in the real world, people are going to want to have sex. With protection used every time, properly, they reduce the risk dramatically, to a very very low degree (check out the medical research on this).
Couples with one negative and one positive must decide themselves whether they wish to take this very small risk in order to live a normal (protected) sexual life, and I don't believe it is anyone's place to decide for them.