Isopropyl alcohol on the tiles, washing up liquid on the cups - might give you a better bond.
However, rawl plugs and stainless screws affixing a brass wire caddy would (and is) be my choice.
@Dammit started
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Isopropyl alcohol on the tiles, washing up liquid on the cups - might give you a better bond.
However, rawl plugs and stainless screws affixing a brass wire caddy would (and is) be my choice.