Keyboard Cleaning

Welcome to the Apple Support Communities.

You need to contact Apple Support for service options: Get Support. They can clean and replace components in your Mac as needed. Even if the keys just feel sticky now, unfortunately, there is almost certainly lots of liquid damage throughout your Mac and damaged parts. This means that this Apple Support article doesn't necessarily help in your case: How to clean the keyboard of your MacBook or MacBook Pro - Apple Support.

I recommend you read Liquid damage to Mac computers and accessories not covered by warranty - Apple Support.

Only go to Apple, an Apple Authorized Service Provider, or send your device to Apple for service (if applicable or available). Do not go to a 3rd party/unauthorized repair center or attempt a repair yourself. This is for the assurance of authorized and professional repairs that use genuine Apple parts. Please refer to this from Apple Support:

Beware of counterfeit parts

Some counterfeit and third party power adapters and batteries may not be designed properly and could result in safety issues. To ensure you receive a genuine Apple battery during a battery replacement, we recommend visiting an Apple Store or Apple Authorized Service Provider. If you need a replacement adapter to charge your Apple device, we recommend getting an Apple power adapter.

Also non-genuine replacement displays may have compromised visual quality and may fail to work correctly. Apple-certified screen repairs are performed by trusted experts who use genuine Apple parts.

Jack