is this really true that fruit diet can wash away all ur sickness in body?

Yes it's true. Fruit has about 80% of water (just like our body). Water will get all the toxic out of your body (so drink water). Fruit also has all the vitamines plus minerals your body needs (unless you only eat 1 kind of fruit). Rice contains nothing that is really worthfull, you have to add a lot to stay really healthy. There are books written about it: Fit for life is the title I believe. Here they also say it's good to have 2-3 fruit weeks every .. weeks a year. You can try it out, you have nothing to loose.

I think it is very tasteful, but you better can just eat much different thing and not only fruit. Because you also need other things than vitamins from fruit. Because every evening rice meals with fruit is going be boring after a week, so i think the best thing you can do to stay healthy is do not eat to much between meals. Or only very healthy things between meals.