Can you prevent me from accessing the crypto rewards earned by Foggie Max?

No.

Every Foggie Max owner will have their own decentralized crypto wallet.  Crypto tokens earned from sharing storage capacity will automatically appear in that crypto wallet.

The crypto wallet is completely decentralized.  Only you have access to your crypto wallet. No one else has access to your crypto wallet.  It will be impossible for Fog Works to “lock you out” of your own crypto wallet.