Sealing between bath & tiles

[nailedit!]

Can anybody help please?
I stood on the sides of my bath to move down the shower head my 6' 5" son left at the top of the rail, and the plastic sealing strip came away from the edge of the bath.
I've cleaned it up and removed all the old silicone, but whoever tiled the wall left some fairly large gaps between tiles and bath (up to .5cm), so there are big gaps.
Should I fill these in with grout before replacing the strip with new silicone, or could I just use plenty of grout and fit the strip on top - would it stick and stay fixed and sealed? :?

[plumbbob]

Don't use grout between a bath or any other fitting and wall tiles. Grout does not flex and as soon as any weight flexes the bath it will crack and allow water to leak.

Half a cm is not that wide so make sure it is completely dry and fill it with silicone. Use it to stick the strip back as well. Allow 24 or better, 48hrs to cure before standing in the bath again.